1. Field of the Invention
The present invention relates to a technology of analyzing the storage capacity of a land for the underground storage of carbon dioxide and the injection characteristic of the land for the underground storage of the carbon dioxide. In more detail, the present invention relates to a method and an apparatus for measuring porosity and permeability of a carbon dioxide underground storage medium, capable of measuring the porosity and the permeability of the carbon dioxide underground storage medium by using one device, and continuously measuring the variation characteristic in the porosity and the permeability of the carbon dioxide underground storage medium according to salt precipitation.
2. Description of the Related Art
When storing carbon dioxide (CO2) under the ground, the porosity and the permeability of a storage medium reflecting the storage capacity and the injection characteristic of the land must be measured.
In general, the porosity and the permeability of a carbon dioxide underground storage medium are measured through an indoor experiment for the core sample acquired from a stratum in which the carbon dioxide is stored.
According to the related art, the porosity and the permeability of the core sample are separately measured by using different devices. In other words, according to the related art, after putting a core sample acquired from the stratum is into a holder for a porosity measuring device and introducing the holder into the porosity measuring device, the porosity of the core sample is measured in the state that a confining pressure is applied to the holder in order to realize an underground environment. If the porosity of the core sample has been finished, the confining pressure of the holder is released and the core sample is drawn from the holder. Then, after putting the core sample into a holder for a permeability measuring apparatus and introducing the holder into the permeability measuring apparatus, the permeability of the core sample is measured in the state that a confining pressure is applied to the holder in order to realize an underground environment.
As described above, according to the related art, since the porosity and the permeability of the core sample are separately measured, the device cost and the required time are increased. In particular, according to the related art, since the procedure of applying and releasing the confining pressure is repeatedly performed with respect to the same core sample, the core sample is denaturalized, so that the characteristic value of the core sample cannot be obtained.
Meanwhile, when supercritical carbon dioxide is stored under the ground, salt, which has been precipitated in the pores of the carbon dioxide underground storage medium, must be considered.
In general, salt water exists in the pores of the carbon dioxide underground storage medium. In this case, water of the salt water is evaporated due to the supercritical carbon dioxide, so that the salt is precipitated. The precipitated salt is filled in the pores of the underground storage medium, so that the porosity and the permeability are reduced. In other words, the porosity and the permeability coefficient of the underground storage medium are varied according to the injection time or the injected amount of the supercritical carbon dioxide.
Although the variation characteristic in the porosity and the permeability serves as an important factor in estimating a carbon dioxide underground storage land, the porosity measuring device or the permeability measuring device according to the related art cannot measure the continuous variation of the porosity and the permeability coefficient according to the salt precipitation.
The related art of the present invention includes Korean Unexamined Patent Publication No. 10-2003-0077055 (published in Oct. 1, 2003).